They say the arrival of warmer weather brings an increase in break-ins as people unwittingly invite criminals into their homes.

Insp Nigel Groom, head of the Cheshire Police’s Eastern area burglary unit, said: “At this time of year people begin spending more time outside and everything becomes a bit more relaxed.

“They leave their door unlocked because they are not very far away. They don’t think about the possibility of someone nipping into their home while they are just a few yards down garden the path. But it happens.

“We’re running a campaign to encourage people to keep doors locked at all times, whether in or out of the house. A third of burglaries in this area are carried out by those who specialise in sneak-ins. They’re just looking for a door that isn’t locked. Simply turning a key can be very effective crime prevention!

“During Spring and summer, people also leave garden tools lying about; sometimes overnight. That’s a big invitation to a criminal, too. A spade or trowel or hoe turns into a lever for forcing a door or window open.

“Tools should be kept locked away when not in use. If they are in a shed, make sure the hasp is fitted firmly and use a quality padlock. It’s also a good idea to padlock tools together. It makes them more difficult to move and use.

“We spend a lot of time identifying and arresting burglars and collecting evidence to prosecute them, but people must accept responsibility for protecting their homes against crime.

“Keep an eye open for anyone acting suspiciously in your neighbourhood. Burglars look around for vulnerable houses and the sneak thieves dodge in and out of gardens, trying doors.”